This invention relates to electrical conductor devices, and, more particularly, to a coaxial cable conductor for high frequency, high voltage electrical feeds.
Many types of devices require high frequency, high voltage power. As an example, a radar-guided missile having an onboard radar transmitter/receiver must have a conductor that conveys such power from a power supply to the radar unit. The radar unit is mounted in the nose of the missile on a gimballed support, and the power supply is located behind the nose. A coaxial cable conductor extends between the two, and conducts the power while permitting the radar unit to be rotated on the gimbal to be aimed at targets. About six separate coaxial cable conductors are required in a typical missile design, ranging from about 1 inch to about 6 inches in length. In some cases the conductors are straight and in other cases have one or more right-angle bends.
The coaxial cable conductor has a solid rodlike center conductor and an outer, hollow cylindrical conductor, with the center conductor centered within the outer conductor by spacers. One type of coaxial cable conductor, termed a semi-rigid coaxial conductor, uses a finned, extruded dielectric material such as teflon which runs the length of the coaxial line assembly. The teflon allows the assembly to be bent into shape while keeping the center conductor centered in place. Connections are soldered or crimped to the ends of the semi-rigid assembly. Because of the large amount of teflon used, this assembly will not handle high power radar energy.
Another type of coaxial cable conductor uses an air dielectric. In the conventional practice for air dielectric coaxial conductor, the coaxial cable conductor is prepared by placing a center conductor with attached spacers into a mold, and filling the mold with wax. The center conductor and wax are removed from the mold. The outer surface of the wax is metallized and electroplated with a copper alloy to form the outer conductor. The wax is removed, and end attachment flanges are affixed to the outer conductor by welding, soldering, or other process.
The process for preparing the air-dielectric coaxial conductor is time consuming and requires extensive handwork, and the resulting coaxial cable conductor is expensive. There is a need for an improved approach to the fabrication of air-insulated coaxial cable conductors. The present invention fulfills this need, and further provides related advantages.